Carburetor



Patented Nov. l, 1932 PATENT OFFICE 'WILHELM WEMHNER, OFBERLIN-NIEDERSCHONWEIDE, GERMANY CABBUBETOR Application led September23, 1930, Serial No.

This invention relates to a carburetor with variable air passagecross-section, and i t consists substantially in that the cross-sectlonof the narrowed portion is changed by the de- 5 pression formed in theinduction pipe behind same. This depression is automatically regulatedaccording to the invention in such a manner, that it automaticallyincreases as the running speed decreases and decreases A as the runningspeed increases. i

In the case of slower running speed therefore the depression isautomatically increased in order to utilize the lower boiling polnt ofthe fuel caused by the vacuum, as also to homogeneously mix the uel andair through the good eddy formation caused by the high iiowlng speed ofthe gas in the variable narrowed portion, and to surely prevent theknocking of the engine by throttllng also 2o with increased compression,in spite of the use of pure benzine.

In the case of faster running speed however the cylinders receive the.full charge through the reduction of the depression, so

that the thermic degree of eiiiciency is considerably increased.

In order to automatically regulate the under-pressure in the inductionpipe of the engine, a movable piston is preferably used 1n the form ofconstruction lllustrated by way of example, the upper face of whichpiston is however loaded by the outer atmosphere so that the piston atchanging speed is moved in opposition to the direction of the induction.An atomizing element, for example a plate atomizer, is connected withthe piston,

which at the same time forms the shutting-oii` element of the inductionpipe leading to the engine. This shutting off position is ensured by aspring bearing on the piston and arranged on levers in such aV manner,that, on the moving of the piston and opening of the induction pipe, theloading of the spring is more or less removed. Thus, aloading which isinverse to the running speed of the engine is obtained, and consequentlythe inverse ratio of thedepression in the induction to the running speedof the engine is established.

An embodiment of the invention is illusf- 483,822, and in Great BritainAugust 11, 1930.

trated by way of example in the accompanying drawing in which Fig. 1 isa vertical section through the rcarburetor.

(Iiiig. 2 is one side view of the carburetor 55 an Fig. 3 is anotherside view of the same.

A piston a is arranged to move up and down on a column c fixed in thecarburetor b. The piston a is extended upwardly like a piston rod andcarries on this extension theatomizer device, for example a plateatomi-` zer, consisting of plates d1 and d2. The bore in the column cleads to the space situated under the piston, whereas the cover side` of5 the piston communicates with the atmosphere through an aperture e. Thepacking of the piston is eli'ected by a leather diaphragm f, which istied on or Aotherwise fixed c to the carburetor casing at one edge andto the piston at the other edge. The piston is acted upon by a spring gshown in Fig. 3, which is adjustably fastened at one end to an elbowlever h1, k2 and at the other end to an elbow lever il, i2. The elbowlever h1, h2 is 75 pivoted at h on the carburetor casing, and the elbowlever il, i2 is oscillatably mounted on a sha-ft k journaled in thecarburetor casing, on which shaft one or several levers Z (Fig. l) arekeyed, which engage under a collar a1 of the piston a. In inoperative4osition the spring g loads the piston in suc a manner that the plateatomizer d1, d2 shuts oif the induction channel myleading to the engine,in which ,channel an air funnel n is 35 arranged for this purpose.

If therefore the engine sucks through the induction channel m the funneln and the bore of the column c, the at-mosphere on the piston pressesthe piston into the position, shown in Fig. 1, so that, in spite of thetensioning of the spring` g, this spring is relieved when the piston isin the position shown, as the lever arms LZ and 2, rolling the one onthe other and which are moved vfrom the dotted position shown in Fig. 3,into the position shown in full line atthe strokes of the piston,the-operatinglever arms alter in such a manner that the lever arm h2becomes continually longer, whereas the lever arm z'1 becomescontinually 101` Cil shorter, until in the extreme position shown inFig. 3, the lever arm l is equal to zero and the loading of the springis removed from the piston, as this sring act-s perpendicularly on theshaft 7c. esides the elbow lever il, i2 and catch levers Z-for thepiston a a fuel control lever 2 is also mounted on the shaft lopreferably on they side of the carburetor, opposite to that on which thespring g is arranged. 'lhis lever o, which in the example shown is inthe form of a segment-like disc, has a top pin o1 adapted to beadjustably inserted in diderent bores o2 and o3. This pin bears againstan arm p oscillatable around p and which shifts by friction an arm g1,actuating the fuel needle. The fuel needle is spring loaded.

lf the pin o1 isin the bore shown in Fig. 2, the needle g opens at thebeginning of the stroke, that is at the commencement of the induction,first quickly and then slowly. lf however the pin is in the bore 02, asubstantially uniform stroke speed of the needle is obtained during thepiston stroke, whereas in position 03 the needle opens slowly at thebeginning of the stroke and then quickly in comparison to the pistonspeed. The friction between the arms p1 and Q1 enables, when adjustingthe pin or the needle, an immediateA bearing of the arm p1 against thepin o1, so that an idle movement between .the levers o and p1 isprevented.

The above mentioned fuel needle q controls the fuel admissionv in knownmanner. rlhe fuel, which enters the carburetor at fr, passes through amovable pipe s, after having been controlled by the needle g,'into thepiston and arrives in an annular channel da, whence it passes throughupwardly inclined passages d4 between the plates d1 and d2. The lowerplate is perforated from the outer side by passages d5 extendingsubstantially perpendicular to the passages'di; The passages 14 and d5communicate at their admission point between the plates in such a mannerthat the outer air forcing its Way in through the passages d5, atomizesthe fuel jet, entering through the passages d4.

Below the piston a and separated therefrom by a casing wall, a diaphragmt of resistant material is arranged. The space situated under thediaphragm communicates with the induction chamber through the fuelconduit, whereas, like the above described piston a, the space situatedabove the diaphragm t communicates with the atmosphere through channelsg. A valve cone o is rigidly connected with the diaphragm, which cone isacted upon by a `spring o1 in such a manner that, when the carburetor isin the inoperative position, the valve c is closed. Only when the enginecommences to suck and the atmosphere entering at u presses the diaphragmdownwards, does the valve o open and uncover the passage for the fuel tothe regulating needle.

.nseaeea This valve is provided, in order to compensate for the dierencein height between the tank and the carburetor. The valve consequentlyonly opens, when a depression exists under the diaphragm t. rlhe valve omust be so set that variations in the height of the reservoir, oroverpressure `occuring therein, does not e'etl: the quantity of fuelowing out on the Dee e.

Having thus described the construction of the carburetor, the operationthereof will he explained so that it is quite clear.

lin principle the carburetor only receives further fuel, when the valve'v opens, that is, when a certain depression exists under the diaphragmt. rThe engine then sucks the fuel through the valve fv, the conduit w,the needle valve Q, the hose 8 through the piston bore land the atomizer(Z1, 022. According to the adjustment of the throttle valve, oraccording to the suction energy, the atmosphere, acting on the piston a,presses the piston a downwards to a greater or lesser extent against theaction of the spring g, so that the s ace situated under the piston a,and there ore the depression existing therein, is reduced until in theposition shown in Fig. l, that is at full speed and with the maximumcross section of the funnel n, the additional loading of the lever k1,h2 of the spring g iscut out in the manner described. Consequently thepiston ais relieved of this additional loading. Thus the loadinginversely to the running speed of the speed vof the engine is obtained.rllhe spring g may be suspended on the arms h1 and 2 at di'erentdistances from the pivot points, in order thereby to regulate anydesired depression ratio in the induction line.

The carburetor casing preferably consists of two main parts al,z2,-connected by a clamp screw y (Fig. 3). This dividing of the casingis advantageous .in that the upper part a with the throttle valve can beadapted to the type of car, so that only by changing the atomizer platesone and the same main part bf the carburetor can be used for all sizesof cars.

I claim:

l. A carburetor with changeable air cross section for internalcombustion engines, comprising in combination with the inductionconduit, a carburetor casing, a column rigidly mounted in said casing, apiston on said column movable in opposite directions to thedirection-lof induction said piston communicating onthe bottom side withthe suction chamber and on the upper side with the atmosphere, a springadapted to additionally load said piston in such a manner that theadditional load thereby also the depression in the induction pipedecreases at increasing engine speed and inversely, and a toggle leverto an arm of which'said spring is attached so that the leverarm of saidspring decreases when said piston is ascending until at maximum strokethe additional sprin loading onvthe piston is neutralized by sai leverarm.

2. A carburetor with changeable air cross section for internalcombustion engines, comprising in combination with the induction vconduit, a funnel in said induction pipe, a

carburetor casing, a column rigidly mounted in said casing', a piston onsaid column movable in opposite direction to the direction of induction,said piston communicating on the bottom side with the suction chamberand v on the upper side with the atmosphere, a spring adapted toadditionally load said piston in such a manner that the additional loadthereby also the depression in the induction pipe decreases atincreasing engine speed and inversely, a leather cup packing saidpiston, two atomizer plates on the top end of said piston forming at thesame -time the closing element for said funnel, and a flexible hoseadapted to supply fuel to said movable piston.

3. A carburetor with changeable air cross section for internalcombustion engines, comprising,v in combination with the inductionconduit, a funnel in said induction pipe, a fuel control needle, acarburetor casing, a column for said funnel, and a flexible hose adaptedto supply fuel to said movable piston.

WILHELM 'WEMHN rigidly mounted in said casing, a piston on sald columnmovable in opposite direction to the vdirection of induction, saidpiston communicating on the bottom side with the suction chamber and ontheupper side with the atmosphere, a spring adapted to additionally loadsaid piston in such a manner that the additional load thereby also thedepression in the induction pipe decreases at increasing engine speedand inversely, acleather cup packlng said piston, two atomizer plates onthe top end of said piston forming at the same time the closing elementsfor said funnel, a flexible e hose adapted to supply fuel to saidmovable piston, a lever oscillating with said piston, a shaft at theside of said piston, a lever arm downwardly extending from said shaftadapted to be actuated by said piston lever, and a laterally directedlever arm on said shaft adapted to be actuated by friction from saiddownwardly directed lever arm and to actuate in turn said fuel controlneedle so that said needle is raised and lowered practically uniformlyrelative to the piston movement in the beginning quickly and then moreslowly, and inversely., f

4. A carburetor with changeable air cross section for internalcombustion engines, com# -prising in combination with the ,inductionconduit, a funnel in said induction pipe, a carburetor casing, a columnri 'dly mounted in said casing, a piston on sai column movable inopposite direction to the direction of induction said pistoncommunicating on the bottom side with the suction chamber and on theupper` side with the atmosphere, a spring n 'forming at the same timethe closing elements 75 In testimony whereof I aiiix my signature. v

